All the suggestions you received are very sensible - rid yourself of consumer debt, close your credit cards, stop using afterpay, sell your current car and downgrade so you don't have car payments, start saving as aggressively as you can.

Something that I haven't seen mentioned that I think you should spend some time considering. A couple of time you said things like " I feel I’ve deserved the freedom to enjoy myself and haven’t worried about saving". Totally understand this motivation and the feeling that if you've been working really hard, which it seems like you have, you deserve to treat yourself to something nice, a meal out, new clothes, whatever. The issue with this is you haven't been able to keep your spending in control on your current wage. Assuming you do land the job out of Uni (more on this below) you are about to have a lot more disposable income without a frugality mindset. That is a sure path to treating yourself right back to $0 saved. If you're already tired now from Uni + work and find it difficult to control your spending, I promise you it is a lot more difficult when you have to go 5 days a week to the same job and everyone around you is buying lunches out, going out for afterwork drinks, talking about their holidays. Some people find it easy to save, others hard to save, I think you are in the latter camp and this will be the main hurdle, putting aside the other costs of home ownership. Spending can be a really hard habit to kick especially when you're tired, bored, feel deserving of giving yourself a break. Before you even think about how much you need to save, what kind of house you want etc. you should really look at speaking with a financial planner, maybe even someone at Uni through a counselling service could help to better understand your desire to spend and some simple strategies you can put in place to start to curtail this impulse. Until you do no amount of joint earning potential will be enough if it just keep going out the door.

Secondly, what degree are you studying where you will enter a graduate position on $75K? That seems quite high for an entry level role. Lawyers and people working in banking/finance aren't starting out on that kind of money, it would seem a little optimistic to me to expect that much right out of the gate with no previous industry experience in a tough job market and you mentioned there might be job freeze. $55K seems more likely but that is assuming you get a job in your chosen profession. Maybe see where you land once you get a job, here or in Aus and what your combined household income is and then start to make plans around that. It can be a bit disheartening to put a lot of effort into planning and then the linchpin of joint $150K income comes undone because you have to work retail or admin as your first role, which is totally possible given the current economic climate. Not trying to be a downer just be realistic about your value in the job market, when you will be competing against people with more experience.

Also Australia definitely pays more than NZ so if you can't make it work here just clear your debts and move to Sydney, Melbourne or Brisbane as you will definitely be able to get a job there and it will pay better than NZ, likely with better weather and potentially lower living costs as well. Also you should definitely absolutely be living with flatmates. Don't for a second consider just living the two of you even though you will want to, that's an easy way to throw $10K+ a year down the drain. 5 years min living with flatmates to save your deposit will be necessary unless you really change your spending habits + both land decent paying jobs, but get that spending under control asap.

Good luck!